Efficacy of Mirror Biofeedback Rehabilitation on Synkinesis in Acute Stage Facial Palsy in Children

Objectives: To evaluate the efficacy of mirror biofeedback rehabilitation for synkinesis in severe acute facial paralysis in children.

Methods: Eight pediatric patients with facial paralysis with an initial electroneurography (ENoG) value less than 10% who underwent mirror biofeedback rehabilitation (the child-rehabilitation group) were enrolled. Seven infants (under age 2 yr) who were unable to undergo rehabilitation (the infant-and-toddler control group) and adult patients (n = 13, range, 33-56 yr) who underwent rehabilitation (the adult-rehabilitation group) comprised the control groups. All the patients enrolled were baseline House-Brackmann (H-B) grade VI at onset. The patients began daily facial biofeedback rehabilitation using a mirror at the first sign of muscle contraction on the affected side and were instructed to keep their eyes symmetrically open using a mirror during mouth movements. The training was continued for 12 months after the onset of facial paralysis. The degree of oral-ocular synkinesis was evaluated by the degree of asymmetry in eye opening width during mouth movements. The synkinesis index was calculated as a percentage of the interpalpebral space width ([normal side - affected side]/normal side). Statistical analyses used non-parametric tests (the Kruskal-Wallis test and Steel-Dwass posthoc test).

Results: The synkinesis index was significantly lower in the child-rehabilitation group than in the infant-and-toddler control group or the adult-rehabilitation group (p < 0.001).

Conclusion: Children who underwent mirror biofeedback rehabilitation had less synkinesis than the infant-and-toddler control group, suggesting that mirror biofeedback rehabilitation is more effective in preventing the exacerbation of synkinesis in children.